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At least 19 recordsLinked to original sources
PubMed2004

Foam films stabilized by dodecyl maltoside. 1. Film thickness and free energy of film formation.

Foam films stabilized by a sugar-based nonionic surfactant, beta-dodecyl maltoside, are investigated. The film thickness and the film contact angle (which is formed at the transition between the film and the bulk solution) are measured as a function of NaCl concentration, surfactant concentration, and temperature. The film thickness measurements provide information about the balance of the surface forces in the film whereas the contact angle measurements provide information about the specific film interaction free energy. The use of the glass ring cell and the thin film pressure balance methods enables studies under a large variety of conditions. Thick foam films are formed at low electrolyte concentration. The film thickness decreases (respectively the absolute value of the interaction film free energy increases) with the increase of the electrolyte concentration according to the classical DLVO theory. This indicates the existence of a repulsive double layer electrostatic component of the disjoining pressure. An electrostatic double layer potential of 16 mV was calculated from the data. A decrease of the film thickness on increase of the surfactant concentration in the solution is observed. The results are interpreted on the basis of the assumption that the surface double layer potential originates in the adsorption of hydroxyl ions at the film surfaces. These ions are expelled from the surface at higher surfactant concentration.

Journal Article↗
PubMed1999

The influence of storage conditions on film characteristics of Ektaspeed plus and Ultra-speed films.

BACKGROUND: Dental professionals were reluctant to accept Ektaspeed (Eastman Kodak Co.) intraoral film despite its X-radiation dose-sparing advantages for patients. One reason may have been Ektaspeed film's known sensitivity to long-term storage as compared with that of Ultra-speed film (Eastman Kodak Co.). In 1995, Kodak replaced Ektaspeed with Ektaspeed Plus, claiming it had better resolution and higher stability than Ektaspeed, as well as equal exposure radiation. The authors compared film response to storage condition and time for Ultra-speed and Ektaspeed Plus films. METHODS: The authors stored 10 boxes of newly produced Ultra-speed and Ektaspeed Plus film in five locations. They conducted 23 image trials over a 26-month period, exposing each film with an aluminum step-wedge under controlled conditions. After processing the film, they measured density to calculate the film's base + fog and contrast index values. RESULTS: The authors found significant differences in film type (P = .0002), processing status (P < .0001), storage location (P < .0001) and month of storage (P < .0001). They also found a film-type-by-location interaction (P < .0001) but did not find a film-type-by-processing interaction (P = .3271). Regression lines suggested that the optical density of base + fog levels rose more steeply for Ultra-speed film than they did for Ektaspeed Plus film. A significant association of decreasing contrast with increasing months of storage was seen with Ultra-speed film (P < .0001). There was a small increase in base + fog levels resulting from the use of used solutions over the course of the study. CONCLUSIONS: Ektaspeed Plus film compared favorably with Ultra-speed film under all conditions. CLINICAL IMPLICATIONS: The authors recommend the use of Ektaspeed Plus film for intraoral imaging, as its performance is comparable to that of Ultra-speed film while requiring half the X-radiation exposure to patients. Clinicians must ensure that the correct safelights and processing solutions are used before switching to the new film.

Analysis of Variance↗
PubMed2001

Directional dependence in film dosimetry: radiographic and radiochromic film.

The trend towards conformal, intensity modulated radiotherapy treatments has established the need for a true integrating dosimeter. In traditional radiotherapy, radiographic film dosimetry is commonly used. The accuracy and reproducibility of film optical density as an indicator of dose is influenced by several variables, including the chemical processing conditions. As a result radiochromic film, with all the advantages of radiographic film but without the need for chemical processing, has increased in popularity, although the low-dose sensitivity of radiochromic film does remain a disadvantage for some experiments. Several studies have investigated the reproducibility of radiochromic film results, but none have specifically addressed the well-known directional dependence seen with traditional radiographic film. In this study, the directional dependence of radiographic (Kodak X-omat V) and radiochromic (Gafchromic) films were measured. It was found that both films over responded when exposed parallel to the central axis of the beam as opposed to perpendicular exposure. An attempt is made to explain the reason for the responses of both films in terms of spectral effects and the air gap between the phantom segments. Although radiographic film exposed parallel rather than perpendicular to the central axis of the beam exhibits a measured difference in film response at depth, this over response does not occur when the extent of the film is restricted to a small region at the centre of the phantom (in this case an air gap is not introduced across the phantom). This suggests that it is the air gap rather than the orientation of the film that is the cause of the over response. Furthermore, when film occupies a slice through the entire phantom an over response occurs for both radiographic and radiochromic film, indicating that spectral effects are not the cause.

Film Dosimetry↗
PubMed2006

Alginate-magnesium aluminum silicate films: effect of plasticizers on film properties, drug permeation and drug release from coated tablets.

The effect of hydrophilic plasticizers, namely glycerin and polyethylene glycol 400 (PEG400), on physicochemical properties of sodium alginate-magnesium aluminum silicate (SA-MAS) microcomposite films was characterized and application of the films for controlling drug release from tablets was evaluated as well. The plasticizers could possibly interact with SA or MAS by formation of hydrogen bonding, as revealed using FTIR spectroscopy. PXRD studies presented that glycerin or PEG400 could intercalate into the silicate layers of MAS and higher crystallinity of the films with PEG400 was obtained. This led to a different thermal behavior of the films. Glycerin gave more flexibility of the films than PEG400. Incorporation of plasticizers into the films did not affect water uptake in acid medium, but increasing an erosion of the films because of the leaching of the plasticizers. Water vapor permeability of the films decreased with increasing amount of plasticizers in the range of 10-30% (w/w). Diffusion coefficient (D) of acetaminophen (ACT) across the films in acid medium increased with addition of the plasticizers because the leaching of plasticizers could reduce tortuosity of aqueous pore channels of the films. The tablets coated with plasticized films had a quite smooth surface without defect as shown by SEM. The ACT release profiles from the coated tablets showed a zero-order release kinetic with drug diffusion mechanism across in situ insoluble composite films in acid medium, and coating film swelling and erosion mechanism in pH 6.8 phosphate buffer. Moreover, neither the release rate nor the release pattern of the ACT coated tablets was obviously changed. The findings show that glycerin or PEG400 could improve physicochemical properties of the SA-MAS films and the plasticized films could control the drug release from tablets in gastro-intestinal condition.

Acetaminophen↗
PubMedDate not supplied

A two-film versus a four-film bite-wing examination for caries diagnosis in adults.

The aim of this study was to compare the caries diagnostic outcome of a two-film and a four-film routine bite-wing examination undertaken in an adult population. A digital bite-wing examination using two and four films, respectively, was performed in 174 patients. The radiographs from the two examinations were assessed jointly by 2 observers for the number of imaged surfaces in the area from the distal surface of the canine to the distal surface of the third molar and for the detection of carious lesions. Significantly more surfaces were available for examination by the four-film than by the two-film examination. Overlapping surfaces were recorded in 14 and 10%, respectively, of the surfaces imaged by the two-film and four-film set. The prevalence of primary enamel and dentinal caries was 6.8% with the two-film and 5.6% with the four-film method. In 1, 684 surfaces only imaged by the four-film method caries was detected in 20 surfaces. If these extra lesions were added to the number of lesions found by the two-film method the total disease prevalence using the last-mentioned method would increase by 2 per thousand. The majority (92-99%) of all recorded lesions were detected in surfaces located between the occlusal surface of the first premolar and the mesial surface of the third molar. The little additional diagnostic outcome obtained by the use of four instead of two films did not seem to match the extra resources (double patient charge and radiation dose, and extended scan/developing and recording time for the dentist) connected to the four-film method. Thus, it may be recommended that a routine bite-wing examination undertaken in young adults should be performed with only two films: one in each side of the mouth, placed behind the premolars and the first and second molars.

Adult↗
PubMed1998

[Monitor assessment of digitalized and post-processed portal films compared to conventional films presented on a light box].

PURPOSE: Judgement of image quality and detail recognition of digitized and post-processed portal films presented on a computer monitor compared to the present standard, conventional portal films presented on a light box. MATERIALS AND METHODS: Conventional portal films of 3 different tumor sites (10 pelvis, 10 cranium, 10 vertebral column) were presented to a panel of 8 observers in 3 different matters: conventional film presented on a light box (Conv), digitized post-processed images (Dig-1) and digitized post-processed images (Dig-2) presented on a high resolution computer monitor. Subjective judgement of image quality, detailed recognition and time requirement of conventional films compared to monitor presentation were evaluated using a 5-scaled questionnaire (from 1 = much better to 5 = much worse). Furthermore the observers had to point out predefined anatomical bony structure on the conventional films (Conv) as well as on the digitized post-processed images (Dig-2). Standard deviations of the landmark outlined by 10 different observers were used as a criterion of objective detail recognition (Figure 1). RESULTS: Image quality of digitized post-processed images presented on the computer monitor was judged statistical significant better than that of conventional films (pelvis 78%, vertebral column 62%, cranium 45% better) (Figure 3). Similar results were found for comparison of detail recognition: digitized post-processed images were scored better for pelvis in 81%, for vertebral column in 57%, for cranium in 40% (Figure 4, Table 1). Most benefit from portal film enhancement was found for pelvic images, where portal films are known to be of poor image quality (Figure 2). In contrast image quality of non-processed digital images compared to conventional films was graded worse (pelvis 69%, vertebral column 53%, cranium 71% worse) (Figure 4). Digital post-processed images were especially for the pelvis judged to require less time (pelvis 68%, vertebral column 26%, cranium 8% less time requirement) (figure 5). For the pelvis a statistical significant decrease of standard deviations was found for Dig-2 compared to conventional films, indicating an objective increase of image quality and detailed recognition (Table 2). In case of vertebral column and cranium no significant differences were evaluated (Table 3). CONCLUSIONS: Digitized enhanced portal films presented on a computer monitor resulted in a quicker assessment and equal to better image quality as well as detail recognition compared to conventional films. Non-processed digitized images were judged to be of less image quality.

Data Display↗
PubMed1998

In vivo tear-film thickness determination and implications for tear-film stability.

PURPOSE: Previous measurements of tear-film thickness in vivo are limited and cannot be easily applied in a clinical setting. A novel technique to measure tear-film thickness indirectly is introduced here, requiring only a slit lamp, video camera, and computer. A recent fluid mechanical theory relates tear-film thickness h, to the tear meniscus radius R, tear surface tension or, tear viscosity mu, and upper lid velocity U. This theory yields the result that h/R = 2.12 (microU/sigma)2/3. All parameters except h/R are taken as known physical constants, and R was measured for each subject, allowing the above equation to establish h. Tear-film breakup was also evaluated and correlated with tear-film thickness. METHODS: A clinical study was performed in which aqueous tear-film thickness was determined for 45 subjects, including 24 non-lens subjects, 15 hydrogel contact lens wearers, and 6 RGP lens wearers. R was measured by instilling fluorescein dye in the form of an eyedrop and videotaping the tear meniscus in profile. Tear-film breakup was videotaped through the ocular port of the slit lamp and evaluated based on a severity scale. RESULTS: Aqueous tear-film measurements are in the same range as literature values, with most measured values falling between 6 and 12 microm. Average tear-film thicknesses for non-lens, hydrogel, and RGP subjects are 10.4, 6.5, and 5.8 microm, respectively. Tear-film breakup is most severe in subjects with thin tear films, especially in contact-lens wearers. CONCLUSIONS: Tear-film thickness is an important parameter that varies among individuals. These variations correlate with differences in tear-film stability.

Adult↗
PubMed1990

Effect of varying processing solution temperature on radiographic contrast and relative film speed of dental film.

The aim of this study was to determine the effect of a stepwise rise in temperature on three film types processed in six different processing solutions and to identify the combinations of film, solution and temperature which produced the best results in terms of radiographic contrast and relative film speed. The film types were Agfa Dentus M2, Flow X-ray and Kodak Ultra Speed while the processing solutions were Agfa, Dürr, EBX, Kolchem, MEMS and Pro-tech. An aluminium step-wedge was exposed under standardised conditions. Processing was carried out in a Dürr 245L automatic processor with variable temperature settings from 25 degrees to 35 degrees C. Unexposed films were processed at each temperature setting to determine the base plus fog values. Densitometric readings were taken using a digital densitometer, and the base plug fog values subtracted from each reading. Radiographic contrast and relative film speed were calculated and the data obtained subjected to statistical analysis using Duncan's Multiple Range Test. It could be concluded that, as the processing solution temperature rose from 25 degrees C to 35 degrees C, both radiographic contrast and relative film speed increased. The highest radiographic contrast was obtained by Agfa film in Kolchem solution at 35 degrees C, while Kodak Ultra Speed film in MEMS solution at 35 degrees C gave the highest relative film speed. An acceptable base plus fog level of 0.25 was obtained in the case of Agfa film in combination with Agfa, Dürr and Pro-tech solutions and Flow X-ray film with Dürr solutions. All the other combinations produced a base plug fog level higher than 0.25.

Solutions↗
PubMed1998

[The hemodynamics laboratory without cine film. A comparison between the production costs of 35-mm film and the recordable compact disk].

BACKGROUND: For more than 35 years, cine film has been used as the standard recording medium for coronary angiography. At present, the DICOM and the CD-R format have been established as the standard media for the transport of cardiac angiographic images in place of cine angiographic film. The aim of the study was to compare the media production costs between two cardiac catheterization laboratories, with and without cine film. METHODS: We collected data from two different laboratories in the same geographic area which perform about 1000 procedures/year, using a similar digital x-ray imaging system. In one lab, images are recorded on 35-mm film at 25 frames/sec. In the other one, the image support is based on a CD-R. For each laboratory we considered both direct patient and variable equipment costs. Direct patient costs in the film-lab include: cine film, processing chemicals, processing labor, chemical disposal, maintenance; in the digital lab: CD-R costs and masterization time. Equipment costs in the film-lab include: cine camera, cine film processor and cine projector; in the filmless lab a DICOM formatter and a review workstation. The equipment amortization costs are considered over a three-year period. RESULTS: Total direct patient costs are 90,000 lira for the film and 14,000 lira for the CD-R. Equipment costs are 193,000,000 lira in the film-lab and 150,000,000 lira in the filmless one. Overall cost per patient is 154,300 lira for the cine film and 64,000 lira for the CD-R. CONCLUSIONS: This study shows that the media costs per patient for a digital DICOM CD-R format system are substantially less than for 35-mm film, permitting savings of more than 90,000,000 Italian lira per year in a mid-volume cardiac catheterization laboratory.

Compact Disks↗
PubMed1996

Rapid in vitro tests of surfactant film formation: advantages of the Exerowa black film method.

Based on our research, the natural configuration of surfactant from birth through adulthood takes the form of intraalveolar bubbles. Thus, bubble film analysis would seem to be the specific in vitro testing method for lung surfactant. In the present study we report a battery of five in vitro tests for assessing structural and functional properties of surfactant bubbles and bubble films from hydrophobic extracts, namely, the therapeutic surfactants Survanta (SU) and Infasurf (IN) (full strength and diluted to 3 mg phospholipid/mL) and from aqueous extracts from rabbit lung lavage at 3 mg phospholipid/mL (SAM). Each substrate was assessed by: 1) Shake test: stable bubbles from SU, IN, and SAM (50/50, v/v in 95% ethanol) covered the peripheral surfaces, indicating positive response; bubble production by IN and SAM always exceeded SU; 2) Click test: bubble clicking began immediately in all preparations except for undiluted SU, in which the onset of clicking was delayed more than 40 sec; 3) Pattle's stability test: diameters of SU, IN, and SAM bubbles were unchanged for more than 20 min in aerated solution, indicating stable very low surface tension; 4) bubble generation by gas dispersion from a single capillary: full-strength concentration of SU and IN produced relatively large bubbles-bubble rate (number/min) and size were comparable; all SU bubbles rupture in < 25 min, whereas IN bubbles were stable for > 30 min; and 5) Exerowa black film method: in contrast with each of the preceding methods for studying intact bubbles, the Exerowa method focuses on the contact between bubble films and permits direct observation of film formation and determination of film structure. Stable black films were formed spontaneously by both IN (full strength and diluted) and SAM. Conversely, SU (full strength) formed no black films but stable rheological films. Diluted SU films ruptured in 50% of trials. Since methods 1, 2, and 3 were nondiscriminatory and method 4 produced unphysiologically large bubbles for most mammals, we concluded that the black film method of Exerowa is the most discriminating of the tests studied here. It provides a unique visual record of foam film formation and stability and clearly defines differences relative to both the nature and concentration of the preparations.

Animals↗
PubMed1992

Event-related potentials in the dual task paradigm: P300 discriminates engaging and non-engaging films when film-viewing is the primary task.

Five groups of subjects (11-16/group) were run in three experiments. In each study P300 amplitude and latency were studied as a function of three sensory task conditions: (1) baseline (oddball task: target and non-target tones only); (2) boring film viewing plus oddball task; and (3) exciting film viewing plus oddball task. In Experiment I, target probability was P = 0.22. In Experiments II and III, each of two groups of subjects was run at P = 0.22 or P = 0.33. Two different exciting films and two different boring films were used. Oddball-target amplitude was found to consistently decrease from baseline to boring to exciting film-viewing conditions at P = 0.22. At P = 0.33, the 2-film discrimination was successful in one of two experiments. P300 amplitude consistently differed from baseline to film-viewing conditions. For the non-target (frequent) tones, the smaller P300 amplitudes consistently discriminated boring and exciting films, as well as single from dual tasks. For target P300 latency, single (baseline) and dual (film-watching) conditions were always discriminable, but boring and exciting films were not discriminable. There were no effects on non-target P300 latency. N100 amplitude discriminated baseline and film viewing conditions, but not boring and engaging films.

Boredom↗
PubMed2005

Comparative bioelectrochemical study of core-shell nanocluster films with ordinary layer-by-layer films containing heme proteins and CaCO3 nanoparticles.

Negatively charged heme protein hemoglobin (Hb) or myoglobin (Mb) at pH 9.0 and positively charged poly(diallyldimethylammonium) (PDDA) were alternately adsorbed on the surface of CaCO(3) nanoparticles, forming core-shell CaCO(3)-[PDDA/(protein/PDDA)(m)] ([protein-m]) nanoclusters. Oppositely charged [protein-m] and poly(styrenesulfonate) (PSS) were then assembled layer by layer on various solid substrates, forming {[protein-m]/PSS}(n) films. In the meantime, ordinary layer-by-layer films of heme proteins with CaCO(3) nanoparticles ({protein/CaCO(3)}(n)) were also grown on solid surfaces. Transmission electron microscopy (TEM), ultraviolet-visible (UV-vis) spectroscopy, quartz crystal microbalance (QCM), and cyclic voltammetry (CV) were used to characterize the nanoclusters and monitor the growth of the two types of films. Both kinds of protein films assembled on pyrolytic graphite (PG) electrodes exhibited well-defined, nearly reversible CV reduction-oxidation peaks, characteristic of heme Fe(III)/Fe(II) redox couples, and were used to catalyze the electrochemical reduction of hydrogen peroxide. The {[protein-m]/PSS}(n) films demonstrate distinct advantages over the {protein/CaCO(3)}(n) films due to their larger fraction of electroactive proteins, higher catalytic efficiency, and better thermostability. The penetration experiments of the electroactive probe into these films indicate that the {[protein-m]/PSS}(n) nanocluster films possess more pores or channels than the simple {protein/CaCO(3)}(n) films, which may be beneficial to counterion transport in the charge-hopping mechanism and helpful for the diffusion of catalysis substrates into the films. In addition, the electrochemical and biocatalytic activity of protein nanocluster films can be tailored by controlling the number of bilayers assembled on the nanoparticle cores (m) as well as the film thickness or the number of nanocluster layers on the electrodes (n).

Biochemistry↗
PubMed2006

Fabry-Perot fringes and their application to study the film growth, chain rearrangement, and erosion of hydrogen-bonded PVPON/PAA films.

We observed Fabry-Perot fringes in the absorption spectra of hydrogen-bonded layer-by-layer (LBL) films of poly(vinyl pyrrolidone) (PVPON) and poly(acrylic acid) (PAA), which stem from the interferences between beams transmitted and partially reflected at the highly smooth film-air interface and film-quartz interface. The appearance and disappearance of Fabry-Perot fringes can be used to evaluate the homogeneity of the film. They also provide information about the film thickness. Using this optical phenomenon, with a minimal requirement of instrumentation, we studied the effect of several experimental conditions on the film buildup and structure. The film grows linearly with dipping cycles. Films fabricated from higher molecular weight polymers tend to be thicker. Increasing the concentration of the assembly solutions can also make thicker films. However, films from high molecular weight polymers or high concentration assembly solutions may be heterogeneous and do not display Fabry-Perot fringes in their absorption spectra. The defects in these heterogeneous films can be healed by a postannealing in water or diluted HCl to allow the chain rearrangement to complete. We further found the PVPON/PAA films can be eroded by long-term annealing in water or diluted HCl by monitoring the movement of the Fabry-Perot fringes. In most cases, the erosion rate is constant with annealing time. The erosion rate decreases with a decrease in the pH of the media and an increase in the molecular weight of the polymers.

Journal Article↗
PubMed1993

An investigation into the mechanical and transport properties of aqueous latex films: a new hypothesis for the film-forming mechanism of aqueous dispersion system.

The effects of plasticizer, physical aging, and film-forming temperature on the mechanical and transport properties of films formed from aqueous dispersions of ethylcellulose latex were investigated. The water vapor permeability of latex films was found to decrease with diethyl phthalate to a minimum value and then to increase with diethyl phthalate at higher concentrations. Because of the decrease in free volume and the further coalescence of particles of latex polymer films in the physical aging range, the creep compliance of latex films decreased with physical aging time. Within 60 to 100 degrees C, the film-forming temperature was found to have no effect on the mechanical and transport properties of Aquacoat films. However, since many pinholes formed in the latex films when the film-forming temperature was above 100 degrees C, the water vapor permeability of latex films was higher than that of latex films formed between 60 and 100 degrees C. The formation of films from aqueous latex dispersions is suggested to proceed gradually from the top to the bottom of the latex dispersion in this study.

Cellulose↗
PubMed1976

[Film quality in film mammography. Article II: Signal/noise ratio of the recording system as a quantitative measure of quality. Final evaluation of recording systems (author's transl)].

During consideration of three film mammographic systems (see article I), the concept of signal/noise ratio is developed as a quantitative measure of film quality. The ability to recognise detail related to detail size, film blackening and exposure geometry was studied for various systems, and the quality profiles are discussed. There is a considerable difference in quality between industrial films without screens and film-screen combinations; however, exposure geometry during mammography has a considerable effect which tends to reduce the difference. Consequently, detail sizes of 200 mu to 1,000 mu (including the majority of mammographic micro-calcifications) are shown about equally well. Contrast for the lo-dose system (D = 1.1) is somewhat less than for adequately exposed industrial film (D = 2.0) or for Cronex 75 m with lo-dose screen (D = 1.5 to 2.0). The lo-dose system (D = 1.1) is 8.6 times more sensitive than Cronex 75 m (D = 2.0), and the system Cronex 75 m with lo-dose screens is 11.6 times more sensitive. Over-exposure with the lo-dose system, contrary to industrial film, rapidly leads to unsatisfactory results (loss of contrast and increased granularity for D greater than 1.5). On the other hand it is often not possible to obtain an adequate exposure (D = 2.0) when using industrial film. For these reasons it is often an advantage to examine large breasts (with considerable geometric unsharpness) and the dense breasts of young women with a film-screen combination (eg. lo-dose system) which requires approximately one eighth of the dose necessary for industrial film. For small or easily compressable breasts (little geometric unsharpness) best results are obtained, using an adequate exposure by employing industrial film; radiation dose it then acceptable. Detailed analysis of the systems has shown that the recording system unsharpness of film-screen combinations in mammography should be reduced.

Female↗
PubMedDate not supplied

Photon energy dependence of the sensitivity of radiochromic film and comparison with silver halide film and LiF TLDs used for brachytherapy dosimetry.

There is a new radiochromic film, a highly uniform, thin (100-microns) detector whose sensitive layer (6 microns thick) changes from colorless to blue by dye polymerization without processing, upon exposure to ionizing radiation. Because the dose gradients around brachytherapy sources are steep, the high spatial resolution offered by film dosimetry is an advantage over other detectors such as thermoluminescent dosimeters (TLDs). This compares the photon energy dependence of the sensitivities of GafChromic film, silver halide verification film (Kodak X-Omat V Film), and lithium fluoride TLDs (Harshaw), over the photon energy range 28 keV to 1.7 MeV, which is of interest in brachytherapy. Sensitivity of the radiochromic film is observed to decrease by about 30% as effective photon energy decreases from 1710 keV (4-MV x rays) to 28 keV (60-kV x rays, 2-mm A1 filter). In contrast, the sensitivity of verification film increases by 980% and that of LiF TLDs increases by 41%. The variation of the sensitivity of radiochromic film with photon energy is considerably less than that for silver halide film and similar to that for LiF TLDs, but in the opposite direction. Radiochromic film, like LIF TLDs, does not exhibit the drastic sensitivity changes below 127 keV that silver halide film exhibits. Dose distribution in the immediate vicinity of a high activity (370 GBq) brachytherapy 192Ir source has been mapped using radiochromic film and is presented to illustrate the applicability of this new technology to brachytherapy dosimetry.

Brachytherapy↗
PubMed1987

E-speed dental films processed with rapid chemistry: a comparison with D-speed film.

Image quality of E-speed film processed in four rapid chemistry solutions was evaluated and compared to that of D-speed film. One-hundred-twenty films (60 E-speed and 60 D-speed) were exposed with the use of a quality-control phantom and processed in four different rapid solutions. The images were evaluated for speed, contrast, fog and base, resolution, and granularity, and the useful lifetime of the solutions was determined. E-speed film processed with rapid chemistry produced images equal in quality to D-speed film in the range tested (70 to 90 kVp). Fog and base levels of E-speed film were greater than those of D-speed film. The resolution and granularity of the images were equal and were judged adequate in both film types, regardless of the chemistry used. Rapid processing solutions were found to have a 10% to 15% shorter useful lifetime with E-speed film than with D-speed film. The processing of E-speed film in rapid chemistry is recommended for emergency care and endodontics.

Densitometry↗